LAS VEGAS  Shane Kruchten had been through worse. Lived through worse. Seen much, much worse.

Saturday night, the Marine veteran saw out of only one eye. The disappoint will linger, but the physical wounds will heal. For Kruchten, they already have.

Making his World Series of Fighting debut in the promotion’s ninth live event, the 29-year-old La Mesa resident lost by rear naked choke. Mike Corey, another Marine veteran, secured the victory 2 minutes, 59 seconds into the second round.

“I guess people are watching, seeing how I will rise up and overcome,” Kruchten wrote in a text message from the hospital, where he had gone to have a swollen right eye examined. “I have no choice but to be strong and continue pushing forward.”

A Wisconsin native who enlisted in the Marines on his 17th birthday, Kruchten returned from two tours in Iraq with post-traumatic stress disorder. He subsequently contended with alcohol and drug addiction, his weight at one point reaching 265 pounds. In 2009, he survived a suicide attempt.

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Saturday, fighting in a featherweight bout at 144 pounds, Kruchten lost but survived underneath the lights at the Hard Rock Hotel & Casino. It was the biggest stage yet of his mixed martial arts career, one he said “literally saved my life” in a December interview with the U-T.

Kruchten, who signed a multi-fight contract with WSOF last year, fell to 11-3. A left hook by Corey (13-3-1) connected early in the first round, leaving Kruchten with limited vision in his right eye. By the start of the second, the swelling had closed the eye shut.

Corey, a former Bellator fighter, took advantage. Kruchten, a jiu-jitsu specialist working on his stand-up technique, took away a lesson.